In a signal transmission system, a channel through which a signal travels between a transmitter and a receiver causes the signal to degrade. For example, in a pulse signal highs and lows of the signal become less sharply defined which causes a first symbol to interfere with other symbols before and after the first symbol. In order to output a more precise signal, a decision feedback equalizer is used to reduce the interference generated by the first symbol from other symbols which follow the first symbol. Depending on the quality of the signal received by the receiver, the first symbol may also interfere with symbols separated from the first symbol by one or more intervening symbols. The process continues in an iterative fashion to produce a high quality symbol output.
As technology nodes decrease and a speed of processing increases, a rate at which symbols in the signal are identified acts as a limit on the speed at which information can be transmitted along the channel. In some instances, a minimum amount of time necessary for the feedback equalizer to identify a symbol, i.e., the minimum identification time, is approximately 75 picoseconds (ps). The minimum identification time corresponds to a maximum transmission rate of approximately 5 gigahertz (GHz). When the speed of transmission increases above approximately 5 GHz, the decision feedback equalizer cannot identify the first symbol during a single rise and fall of an evaluation clock signal. In some instances, a decision feedback equalizer having a half rate architecture is used to facilitate identification of the first symbol and later symbols. The half rate architecture de-multiplexes the signal into two separate signals effectively separating the signal into two halves to reduce signal degradation during propagation through the channel. The half rate architecture is complex and increases the size of the circuit used to analyze the signal.